1. Field of the Invention
The invention relates to a writing instrument having a reservoir for writing fluid in the form of a fiber body, which has capillary conduits in the direction of the longitudinal extension of the fibers, and having a housing which receives the writing fluid reservoir and holds a writing tip in its front end. A writing fluid conductor extends coaxially in the writing fluid reservoir and communicates in a fluid-conducting manner with the writing tip.
2. Brief Description of the Prior Art
In a known writing instrument of this kind (British Pat. No. 2,150,506), the writing fluid reservoir comprises a substantially cylindrical fiber body in which the fibers extend in the direction of the longitudinal axis of the cylinder and hence parallel to the writing fluid conductor disposed coaxially in the fiber body. In this known writing instrument, during use for writing or for drawing, the fibers transport the writing fluid received by the reservoir, on the one hand in the direction of the coaxially extending capillary conduits and on the other hand in the radial direction with respect to the conductor. Since the capillary forces in the axially extending capillary conduits are greater than the forces acting on the writing fluid in the radial direction, however, some of the writing fluid contained in the reservoir does not even reach the coaxially extending conductor. Instead, ink is retained in the radially outer regions of the reservoir, so that the reservoir cannot support writing up until actually empty.